Magnetic sensor, sensitivity measurement method thereof, and magnetic field source detection device

Abstract

Disclosed herein is a sensitivity measurement method for measuring a sensitivity of a magnetic sensor provided with a sensor chip having a magnetosensitive element, a magnetism collecting body for collecting a magnetic field to the sensor chip, and a housing for accommodating therein the sensor chip and the magnetism collecting body. The method includes applying a magnetic field to the magnetic sensor, and calculating the sensitivity of the magnetic sensor based on a simple average value of theoretical magnetic field strengths at a plurality of virtual sensitivity points evenly distributed inside the housing and an output value output from the senor chip.

What is claimed is: 
     
         1 . A sensitivity measurement method for measuring a sensitivity of a magnetic sensor provided with a sensor chip having a magnetosensitive element, a magnetism collecting body for collecting a magnetic field to the sensor chip, and a housing for accommodating therein the sensor chip and the magnetism collecting body, the method comprising:
 applying a magnetic field to the magnetic sensor; and   calculating the sensitivity of the magnetic sensor based on a simple average value of theoretical magnetic field strengths at a plurality of virtual sensitivity points evenly distributed inside the housing and an output value output from the senor chip.   
     
     
         2 . The sensitivity measurement method as claimed in  claim 1 , wherein the plurality of the sensitivity points are arranged on the magnetism collecting body and the sensor chip. 
     
     
         3 . The sensitivity measurement method as claimed in  claim 2 ,
 wherein the magnetism collecting body includes first and second magnetism collecting bodies,   wherein the sensor chip is disposed between the first magnetism collecting body and the second magnetism collecting body,   wherein at least one of the plurality of sensitivity points is arranged on the sensor chip, and   wherein remaining ones of the plurality of sensitivity points are arranged on the first and second magnetism collecting bodies.   
     
     
         4 . The sensitivity measurement method as claimed in  claim 3 , wherein a number of the sensitivity points are 10 or more. 
     
     
         5 . A magnetic sensor comprising:
 a sensor chip having a magnetosensitive element;   a magnetism collecting body for collecting a magnetic field to the sensor chip; and   a housing for accommodating therein the sensor chip and the magnetism collecting body,   wherein a sensitivity of the magnetic sensor is measured by applying a magnetic field to the magnetic sensor, and calculating the sensitivity of the magnetic sensor based on a simple average value of theoretical magnetic field strengths at a plurality of virtual sensitivity points evenly distributed inside the housing and an output value output from the senor chip.   
     
     
         6 . A magnetic field source detection device comprising a plurality of magnetic sensor,
 wherein each of the plurality of magnetic sensor includes:
 a sensor chip having a magnetosensitive element; 
 a magnetism collecting body for collecting a magnetic field to the sensor chip; and 
 a housing for accommodating therein the sensor chip and the magnetism collecting body, and 
   wherein a sensitivity of the magnetic sensor is measured by applying a magnetic field to the magnetic sensor, and calculating the sensitivity of the magnetic sensor based on a simple average value of theoretical magnetic field strengths at a plurality of virtual sensitivity points evenly distributed inside the housing and an output value output from the senor chip.